ST. LOUIS (AP) – The Democratic U.S. Senate candidate in Missouri assembles an AR-15 assault rifle – blindfolded – then dares the incumbent Republican to do the same.

The TV ad released Thursday by Jason Kander is the latest salvo in a race that could be a factor in determining control of the Senate.

Incumbent Roy Blunt is a strong gun rights supporter who has the backing of the National Rifle Association. He did not serve in the military. Kander, Missouri’s secretary of state, was an Army intelligence officer in Afghanistan.

A Blunt spokesman says the National Rifle Association gave Kander an “F” grade for opposition to Second Amendment rights.

Saint Louis University political scientist Ken Warren says the ad helps Kander because it shows he knows his way around guns, and it plays up his military background.